Automatic weighing mechanism



May 20, 1952 J. D. CONTI 2,597,069

AUTOMATIC WEIGHING MECHANISM Filed Feb. 18, 1949 4 Sheets-Sheet l INVENTOR.

JOHN D. CONT! May 20, 1952 J. D. CONTI AUTOMATIC WEIGHING MECHANISM 4 Sheets-Sheet 2 Filed Feb. 18, 1949 INVENTOR. JOHN D. C ON T/ May 20, 1952 J. D. coNTl AUTOMATIC WEIGHING MECHANISM 4 Sheets-Sheet 5 Filed Feb. 18, 1949 hm D N M. f; d W

y 20, 1952 J. D. CONT] 2,597,069

AUTOMATIC WEIGHING MECHANISM Filed Feb. 18, 1949 4 Sheets-Sheet 4 mp1: :11: i1 v v INVENTOR.

JOHN D. C ONT/ Patented May 20, 1952 UNITED STATES PATENT OFFICE Claims.

This invention relates to a machine for continuously conveying articles and for automatically interrupting such conveyance for the purpose of weighing each article or group of articles, such as a pile of sheets.

It is an object of the present invention to provide a machine for continuously conveying an article from one stage of processing, such as a package filling stage, to another stage, such as labeling or the like, and to automatically weigh each article or pile thereof as it proceeds between such stages without interrupting the conveyor and without creating a frictional drag of the conveyor over the weighing mechanism or any part thereof. It is an object to provide for such automatic weighing without interruption of the conveyor while separating or lifting the article from gravitational effect upon such conveyor. Further objects and advantages of the invention will be apparent from the drawing and the description thereof hereinafter.

In the drawing, which is illustrative of the invention,

Figure 1 is a plan view of one embodiment of the invention, with parts cut away for clarity of illustration,

Figure 2 is a side elevation thereof, with parts .cut away,

Figure ;3 is a section taken along line IIIIII of Figure 1,

Figure 4 is a section taken on line IVIV of Figure 2,

Figure 5 is a detail view taken on line V-V of Figure 1,

Figure 6 is a front elevation of a modification,

Figure 7 is a plan view of a portion of the embodiment of Figure 6, and

Figure 8 is a section on line VIII-VIII of Fi ure 6.

The present invention may be applied to any suitable conveyor system, and as shown in Figures 1 and 2 especially, the articles may be delivered from stage to stage by means of belts 3 and 4 which proceed about pulleys or drums 5 and 6 respectively which rotate in the direction of the arrows. From the conveyor 3, the articles pass over a conveyor system comprising a plurality of parallel belts I (eight being specifically shown). These belts extend from adjacent the discharge point of the conveyor 3 and the receiving point of conveyor 4, and, optionally, driven rolls 8 may be provided between the ends of belts l and the ends of belts 3 and 4 respectively. to assist transfer from one conveyor to the next. The belts 1 have their upper courses supported by rollers 9 and [0 which are carried rotatably by means of cross shafts II and I2 respectively, supported in the side bars l3 and M which are supported on uprights I5 which are in turn carried upon side frame members I6 extending lengthwise of the conveyor system. Adjustably mounted tension pulleys I! are provided and guide the lower courses of the belts 1.

At any desired position along the conveyor system comprising belts 1, weighing mechanism is provided which may comprise a conventional platform scale the base of which is indicated at I8. The weighing platform is indicated at 19 and carries upon it a plate 20 which supports four upright posts 2| having a reduced section at the top as indicated at 2 la. A weighing support for the article comprises spaced strips extending upwardly from a plate 22 which has four bosses 23 at the corners which have bores making a sliding fit on the reduced-section portions 2la of the posts (see also Fig. 4). The plate 22 carries fixedly upon its upper surface the plurality of spaced strips 24 which are slotted at 25 to allow relative vertical motion between such strips and the shafts l2 without interference. The strips 24 are spaced alternately between the belts 1 and between the side plates I 3 and I4 and. the adjacent belts 'I. When the plate 22 is in its lower position with the bosses 23 resting upon the shoulders between 2| and Zia, the upper surfaces of the strips 24 are below the upper surfaces of belts 1 as clearly shown in Figure 4. However, the slots 25 allow the plate 22 to be elevated so that the strips 24 carried thereby rise above the upper surfaces of the belts as shown by the dotted line position in Figures 2 and 4. As will be explained hereinafter, the rising of this plate and the strips carried thereby serves to lift the article carried by the conveyor to free such article from the translatory motion of the conveyor system comprising belts 1.

The means provided for elevating the plate 22 comprises the links 26, one pivotally connected at one end to each of the four corners of the plate 22 and at their other ends to four levers 21 Each pair of levers 21 are fixedly secured to one of the two cross shafts 28 and 29 rotatably mounted in suitable bearing blocks 38 carried on the plate 29. The shafts 28 and 29 carry gears 3! and 32 fixed thereto by means of keys, set screws, and the like. The gears 31 and 32 are in mesh, and a lever 33 is secured fixedly to the shaft 28.

'The driving mechanism for the weighing support elevating means may comprise afsin'gle-revolution clutch of conventional construction. Such a clutch comprises a core member which may be fixedly secured to a shaft, which is the driver or is to be driven, and a sleeve member about the core member, which may serve to be driven by or to drive the core member, when a trigger or detent lug is released, but the core member and the sleeve member may be prevented from driving each other by restraining such trigger or detent lug. In the present application of the single-revolution clutch 34, a drive chain serves to continuously rotate the sleeve member of the clutch 34, and the detent lug 36 is adapted to be restrained by the detent rod 31 (see especially Figures 2 and 5). A spring 31a normally urges the rod 31 in a clockwise direction into the detent lug restraining position. The core member of the clutch is fixedly secured to a cross shaft 38 upon which there is fixedly mounted an arm 39 which exerts a cam action under lever 33 as it rotates. A roller follower 40 may serve to engage the lever 33 to reduce the friction therebetween. The shaft 38 also carries a cam 4| fixedly secured thereto and this cam has a projection which is adapted to co-operate with the latch means 42 (see Figure 3) which is pivotally mounted at 43 on a lug 44 secured to plate 20 on the platform |9 by means of the bracket 45. The latch comprises three arms integrally connected together. The longer arm 46 is urged by a spring 41 in a counterclockwise direction as viewed in Figure 3 into a notch 46a of a lever 5| which is fixedly secured to the shaft 28, one end of the spring being embedded or otherwise afiixed to arm 46 and the other end being affixed to a peg or post 48 extending from the plate 20. The two smaller arms 49 and 50 of the latch 42 cooperate with the projection of the cam 4| as is apparent from the drawing.

Normally, as shown in the solid line representation in Figure 2, the detent lug 36 is restrained by rod 31 so that the chain 35 drives the sleeve of the clutch 34 without rotating the core thereof or the shaft 38 secured to the core. The rod 31 is pivotally mounted at 52 on a fixed frame member 53 and its upper end is engaged by a lever 54 pivotally mounted at 55 (see Fig. l) The other end of lever 54 is actuated by means of the eccentric or cam 56 fixedly secured to a pin or shaft 51 rotatably mounted in a frame member 58 and carrying fixedly secured to the upper end thereof an arm 59 which serves as a detector element. The arm 59 carries a roller element 60 adapted to be engaged by the article being carried over the conveyor system to the scales.

A chain 61 drives a sprocket 62 secured to a shaft 63 which has fixedly mounted thereon the grooved driving roller 64 for the belts 1. A chain 68 may serve to drive a shaft 69 carrying one of the rolls 8. The other roll 8 adjacent thereto may be driven from shaft 69 by gears 10, 1|, and 12, the latter being fixedly mounted on the shaft 13 carrying such other roll 8.

In operation of the embodiment of Figures 1 to 5, a package or other article being transferred from one place to another is carried by the conveyor 3 on to the conveyor system comprising belts 1 which belts are continuously driven at all times. As the article passes beyond the phantom position shown by the dotted line circle in Figure 1, it swings the detector arm 59 which actuates lever 54 which in turn causes rod 31 to disengage the detent lug 36 of the one-revolution clutch. Upon such release of the detent lug 36, the shaft 38 is rotated in a counterclockwise direction as 4 viewed in Figures 2 and 5 and the lever 33 is lifted by the roller 40 into the dotted line position. This rotates shafts 28 and 29 and causes lever 21 to lift the platform 22 thereby causing the weighing support strips 24 to elevate the package off the belts 1 and transfer the weight of the package or other article entirely to the scale platform |9.

As lever 33 reaches its uppermost position, lever 5| also does so, and the spring 41 causes the latch arm 46 to swing into the solid line position shown in Figure 3. This latch prevents the article lifting mechanism from again descending and since arm 39 continues to rotate, it descends from under lever 33 and there is a distinct separation of the parts carried by the scale platform H! from the parts carried by shaft 38. Hence, it is possible to make an accurate weighing at this time. After a predetermined interval allowing sufficient time for an accurate weighing to be made, the projection of cam 4| reaches the spaced arms 49 and 50 of the latch 42 and as it proceeds in the direction of the arrow (Figure 3) arm 45 is swung out from under lever 5| and the base 22 with the weighing support is allowed to descend into the recessed position with respect to the conveyor belts 1. During such descent, the package or other article carried thereon is transferred to the conveyor belts 1 and automatically carried on to the next stage.

It is desirable when packages of different sizes are to be handled by the mechanism that each package be approximately centered with respect to the weighing platform so as to give the most accurate weighing and to distribute wear evenly on the fulcrum points of the scales. In the embodiment of Figure 6 which shows the conveying means somewhat more diagrammatically, there is shown an adjustment for the purpose of accommodating packages of different sizes and assuring that such packages will be placed upon the scales in approximately the center thereof.

As shown, the article is carried by belts 1a, the upper courses of which are supported by rolls 9a in a manner similar to the previous embodiment. Similarly, the strips 24a of the weighing mechanism intervene between the belts 1a and are adapted to reciprocate vertically with respect thereto. The detector 59a is carried on a slidable block 15 which has a bore through which the fixed guide rod 16 extends. The chain 11 is secured at one end to the block 15 and passes over a sprocket 18 which is freely rotatably mounted on a bearing 19. A weight 89 serves to tension the chain 11. A cord or other flexible strand 8| is attached at 82 to an extension 83 of the block 15 and passes around a pulley 84 to a capstan or Windlass 85. This Windlass is fixedly mounted on a shaft 86 to which a pinion 81 is secured. The pinion is rotated by a gear 88 fixedly secured to shaft 89 to which shaft an arm 90 is fixedly secured. The pulley 84 and the upwardly extending stretch of the strand 8| as well as the Windlass and gear drive therefor may be housed in a casing 9| which has a slot 92 through which a manipulative element 93 may extend. This element has an inwardly projecting portion 94 which telescopes within a bore in the arm 90 and a spring 95 normally urges the extension 94 radially outwardly. This extension 94 is bent into a U-shape and one leg 96 thereof is adapted to engage the inside surface of an arcuate wall 91 in which the slot 92 is provided. The friction of engagement between 96 and the inside of the wall 91 serves to maintain the system in any position to which it is set but allows the application of force to reset the system.

A graduation scale 98 may be provided outside the arcuate wall and indications may be placed thereon to guide an operator in the positioning of the element 93 for any given size of package.

In this modification, an electrical switch is used for operating a solenoid to release the detent lug of the one-revolution clutch. As shown in Figure 7, the switch comprises the movable pole or contactor 99 and the fixed pole or contactor I00. A spring IOI normally urges them apart. The movable pole is mounted on an arm I02 pivotally mounted at I03 and an abutment I04 limits the separation of the pole 99 from I00. Leads I05 and I06 are connected in series with the poles 99 and I00, a source of electric potential I01, and the coil I 08. The core I09 of the relay is normally urged by spring H0 into the position to restrain the detent lug 36 of the one-revolution clutch 34 but upon energization of the coil I08, the core I09 is retracted thereby releasing the detent lug 36 and allowing rotation for one revolution.

The detector 59a has an extension III which carries a pawl or lug II2 pivotally mounted at H3 thereon. A spring H4 normally urges the pawl into the extended position shown in Figure 7 and a detent I I5 prevents the lug I I2 from swinging in a counterclockwise direction about its pivot H3. However, lug II2 may swing in a clockwise direction by a force sufficiently strong to overcome the action of spring I I4. When detector arm 59a swings in clockwise direction, the lug H2 engages the projection H6 secured to the arm I02 and causes pole 09 to contact pole I00 of the switch. When 59a swings on its return stroke, however, the lug I I2 is free to rotate in a clockwise direction about its pivot II3 when it passes back of projection H6 so that there is no closing of the switch on the return stroke. A spring II'I urges detector 59a into the position shown in Figure 7.

In operation of this device, the operator sets the manipulative element 93 to the indication that corresponds to the size of the package to be weighed. The movement of element 93 to such position causes the gear 88 and pinion 87 to either wind up or unwind the windlass 85 thereby shortening or lengthening the strand 8| and moving the block 15 one way or the other along the guide rod 16. This disposes the detector element 59a in the proper position along the conveyor belts Ia for the size of package to be weighed so that when closing of the switch is caused by engagement of lever 59a with the article to be weighed, the scale platform elevating mechanism will be operated at proper time to catch and lift the article as it passes over the approximate center thereof.

It is to be understood that changes and variations may be made without departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

1. In combination, means for conveying something along a path comprising a plurality of parallel, laterally-spaced conveying elements, and means for continuously moving such elements longitudinally, a scale platform, a reciprocable weighing support mounted on the platform and comprising a plurality of spaced strips laterally spaced from the conveying elements, and means for reciprocating the weighing support with respect to the platform between a normal position in which the upper surfaces of the strips are below the upper surfaces of the elements and an elevated position in which they are above the upper surfaces of the elements.

2. A combination in accordance with claim 1 comprising means along the path preceding the weighing support comprising a detector element actuated by the thing being conveyed for initiating operation of the reciprocating means.

3. A combination in accordance with claim 1 comprising latch means carried by the scale platform for retaining the weighing support in elevated position.

4. A combination in accordance with claim 3 comprising means operated in timed relation to the reciprocating means for releasing the latch means.

5. In combination, a frame, means carried by the frame for conveying something along a path comprising a plurality of parallel, laterally spaced elements, means for continuously moving such elements longitudinally, a scale platform, a weighing support mounted reciprocably on the platform, said support comprising a plurality of spaced strips laterally spaced from the conveying elements, means for reciprocating the weighing support between a normal position in which the upper surfaces of the strips are below the upper surfaces of the elements and an elevated position in which they are above the upper surfaces of the elements, latch means on the platform for retaining the support in elevated position, means carried by the frame and normally disengaged from the latch means for releasing the latch means after a predetermined interval.

6. A combination in accordance with claim 5 comprising a movable detector disposed along said path in the way of the thing being conveyed, and means actuated by movement of the detector for intiating operation of the reciprocating means.

'7. A combination in accordance with claim 6 in which the platform carries at least one fixed upright post thereon upon which the support is vertically slidably mounted, at least one rotatable shaft is carried on the platform, an arm is fixed to the shaft, a link connects the support to the arm, lever means is fixed to the shaft, a second shaft is provided on the frame, there is means for rotating the last-mentioned shaft, an arm is fixed to the last-mentioned shaft and is disposed under the lever means whereby to raise the latter once during each revolution of said shaft.

8. The combination according to claim 2 comprising means for varying the position of the detector element along the path.

9. The combination in accordance with claim 8 in which the detector element is mounted on a block which is slidably mounted on a rod extending parallel to the path of the article on the conveyor, a weighted flexible member is provided for pulling the block in one direction along the rod, a flexible strand is attached to the block and extends away from it in a direction opposite to that of the weighted flexible member, and means is provided for moving the strand longitudinally.

10. The combination in accordance with claim 9 in which the means for moving the strand comprises a windlass and indicator means is provided to indicate the relative position of the detector element along the path.

JOHN D. CONTI.

(References on following page) 8 REFERENCES CITED Number Name Date The followin references are of record in the 1,729,991 Bond 1929 file of this patgent; 1,965,302 Wagner July 3,1934 2,038,458 Segebaden Apr. 21, 1936 UNITED STATES PATENTS 5 2,152,339 Anderson Mar. 28, 1939 Number Name Date 2,353,005 Behrent July 4, 1944 1,690,679 Hebden Nov. 6, 1928 

